The gruesome slaying of a St. Paul man who allegedly owed money to a drug dealer gave Ramsey County jurors on Friday a glimpse into an underworld of addicts, killers living under a bridge, and drug lords who terrified underlings with threats to kill them and their families.

On Friday, in the opening day of a second-degree murder trial for Santana Martina Valdez, jurors were told how Andrew W. Braun, 38, bled to death last March after being attacked with a screwdriver, a samurai sword and a bayonet knife.

Valdez's co-defendant, Carlos Yobani Flores Amador, is serving 25 years for the killing, and a third defendant, Maria H. Luna, pleaded guilty to being an accomplice. They were living under a bridge when arrested.

Luna is expected to testify next week that she and the men had gone to Braun's home to collect $12,000 for methamphetamine, which they needed to pay to a drug lord.

Braun's family doesn't believe that he had a drug debt, said his mother, Linda Braun. Still, his family knew that Braun struggled with addiction. He worked many years as a crew member on towboats and barges for harbor service firms in St. Paul.

'Fight to the death'

"He fought desperately for his life," David Miller, assistant Ramsey County attorney, said in opening statements.

Braun's tools and other items, including his samurai sword, were used to inflict much damage on his body, Miller said.

"This was a fight to the death from the get-go," he said. "There would be no turning back."

Braun's body was found in the Payne-Phalen neighborhood by his longtime girlfriend, Tina Heifort, when she returned home about 1:40 a.m. on March 19, she testified.

She said Valdez and his girlfriend, Luna, had been asking Braun for money just hours earlier.

Heifort said that she knew them only as "Uncle" and "Auntie," and that Braun was doing meth "business" with Valdez every day, or every other day. She said Valdez and Luna went to Mexico while they were being investigated for drugs but returned in early 2012.

Co-defendent 'went psycho'

Defense attorney Ellen Seesel told jurors that Valdez did not kill Braun and pointed to Amador, saying that after they went to collect the drug debt, Amador "went psycho" while Valdez looked for money.

"There was never a plan to kill Andrew Braun," Seesel said. "They needed the money because their lives were being threatened."

In a police interview, Valdez admitted to spraying Braun in the face with hair spray, then leaving the room to hunt for money as Amador began stabbing Braun with a screwdriver.

Four months before the slaying, Braun had been arrested, accused of possessing meth as federal drug agents ran a bigger probe, which in the summer of 2011 had identified Valdez as being part of a drug cartel.

Officers searched Braun's house in the 700 block of E. Lawson Avenue in November 2011, seizing 98 grams of meth. Braun told them he was holding it for Mexican traffickers.

Tales of a trafficker

Valdez was born in 1976 in San Fernando, Mexico, about 90 miles south of Brownsville, Texas, his attorney said. Abandoned as a newborn, he was adopted by a family at 10 days old. At age 18, he came to the United States, working as a carpenter, heavy equipment operator and in construction. He sent money home to his family, Seesel said.

About two years ago, he met Luna online. They were together for 18 months before the slaying.

Valdez didn't use drugs, but Luna's brother kept asking him if he could get him some methamphetamine, Seesel said.

So he asked co-workers and was introduced to the trafficker named "Truncas." Seesel described him as a drug lord who was a "puppet master" over his underlings, terrifying them with threats that they or their families would be killed if he didn't get his money.

Luna had told police that she, Valdez and Amador went to Braun's house to collect the $12,000 that he owed for methamphetamine, and that the money was to be given to Truncas. As soon as they arrived, the men allegedly took Braun to the floor and began beating him, she said.